Mr Reilly announced the plan more than three months ago and said he would give food outlets six months to comply with the voluntary scheme. If they did not, he would introduce legislation to force them to comply.

Mr Cummins said many restaurants were struggling to survive through the recession and wouldn’t spend €5,000 on calorie menu labelling. A spokeswoman for the Minister for Health said Mr Reilly would continue to encourage people to join the initiative voluntarily.

“It will be reviewed at the end of the year and then if necessary he will move to legislate in this area.”

The Food Safety Authority of Ireland had recommended that calories be added to menus. A spokesman said feedback suggested that larger food business chains had either implemented or were planning to implement the scheme.

The authority is working on developing various technical tools and training requirements to help restaurants calculate the calorie content of food and drinks they serve.

The Irish Hotels Federation also expressed reservations. Chief executive Tim Fenn said the proposed scheme would be more appropriate for fast-food outlets, cafes and bars, because their menus did not change on a regular basis.

The Bay restaurant in Clontarf had introduced calories on its menu before Mr Reilly recommended it and said it was money well spent. General manager Julian Chambers said the Bay had completely revamped its menu to include details such as allergens and fat, sugar and salt content. When spending on a nutrition course, new menus, consultants and advertising was taken into account, the entire project cost about €10,000.

Mr Chambers said business increased by 40 per cent after the revamp and the restaurant now had its own niche. Restaurant staff had noticed that customers took calories into account, particularly when ordering desserts. Chefs had also become more conscious of calories and if a proposed new dish was particularly high in calories, it might be tweaked to make it healthier.

McDonald’s recently introduced calorie displays on menus in its 12 company-operated restaurants, including outlets at Grafton Street and Henry Street, Dublin, and Maynooth, Co Kildare. A spokeswoman said it was working with its franchisees to introduce calorie displays on menus in its 70 other Irish outlets by early next year.

The River Lee hotel in Cork introduced calorie counts earlier this year following requests from customers. Sales and marketing director Paula Cogan said the cost was not significant. “We timed it so that the menus were due to change anyway.”

She said customers seemed to choose the more healthy options in midweek, “while at weekends guests like to treat themselves to a few extra calories”. The greatest surge in demand was for gluten-free products, she said.